Add swap + immich memory limits after OOM incident

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/server.md

@@ -23,6 +23,7 @@
 | RAM | 7.6 GiB |
 | Disk | 150 GB (`/dev/sda1`) |
 | Volume | `mercury-objects` (id `105925944`), 750 GB ext4 at `/mnt/objects` (fstab, nofail) — MinIO data |
+| Swap | 4 GB swapfile (`/swapfile`, swappiness 10) — added 2026-06-05 after Immich's arrival OOM-killed the Dokploy service (exit 137 loop → bad gateway). Immich server/ML now carry 2g/1.5g mem_limits. |
 | Firewall | Hetzner Cloud Firewall `mercury-web` (id `11085164`): inbound 22/80/443tcp+udp/2222 + ICMP only. Blocks the otherwise-public Dokploy :3000 and Traefik dashboard :8080 (api.insecure). Manage via Hetzner API. |
 
 ## Stack